The present invention relates generally to data storage systems and, more particularly, to an intelligent data storage manager for a virtual data storage system configured to segment virtual tape volumes into atomic units called data pages.
In a virtual data storage system, significant challenges lie in the management of virtual tape volumes written to an intelligent data storage manager from client applications across a storage network. Some of these challenges lie in the areas of access performance and cost of storage. To address these challenges, intelligent data storage managers may rely on some form of hierarchical storage management to shuttle virtual tape volumes, or portions thereof, to different logical and physical devices, depending on storage management attributes and storage management policy.
Other challenges lie in system performance, such as system bandwidth. Virtual tape volumes are often staged on a disk subsystem, which is used as a tape buffer. There often exists a speed mismatch between the input channel and the disk subsystem. Indeed, optimization of sequential write access to the disk subsystem is crucial to overall system performance. Likewise, as virtual tape volumes are written to the back end, i.e., the tape subsystem, speed matching is also desired.
Other challenges lie in large files. A virtual tape volume written by a tape backup application to an intelligent data storage manager may be very large. With a finite sized disk subsystem, an insufficient amount of concurrent virtual tape volume access is possible, unless the unit of storage management is less than a virtual tape volume in size.
To address these challenges, what is needed is an intelligent data storage manager for a virtual data storage system which divides virtual tape volumes into smaller storage units and then manages the storage of these smaller storage units in the virtual data storage system.
Accordingly, it is an object of the present invention to provide an intelligent data storage manager which segments virtual tape volumes into atomic units called data pages optimally sized for storage device performance in a virtual data storage system.
It is another object of the present invention to provide an intelligent data storage manager which selectively stores data pages making up a virtual tape volume on different storage devices in a virtual data storage system.
It is a further object of the present invention to provide an intelligent data storage manager which segments virtual tape volumes into data pages, selectively stores the data pages on different storage devices, and creates a meta data page to map the virtual tape volume blocks to associated data pages.
In carrying out the above objects and other objects, the present invention provides an intelligent data storage manager operational in a virtual data storage system that uses at least one data storage element to store data thereon for at least one host processor connected to the virtual data storage system. The intelligent data storage manager includes a host interface and a controller. The host interface receives a virtual volume having a plurality of virtual blocks from a host processor. The controller sequentially segments the virtual volume into data pages. Each data page includes at least one virtual block of the virtual volume. The controller generates a meta data page associated with the virtual volume to map the data pages to the respective virtual blocks of the virtual volume.
Preferably, the controller uses the meta data page to selectively store the data pages onto the at least one data storage element. Each of the at least one data storage element has a partitioning configuration and the amount of the at least one virtual block included by each data page is a function of the partitioning configuration of each of the at least one data storage element. Each data page preferably includes an identical amount of virtual blocks.
Preferably, the virtual volume is a virtual tape volume and the virtual block is a virtual tape block. The meta data page associated with the virtual volume includes a plurality of meta data page records. Each meta data page record includes a plurality of meta data records and each of the meta data records corresponds to at least one virtual block.
In a preferred embodiment, the at least one data storage element includes at least one high performance data storage element and at least one low performance data storage element. The controller uses the meta data page to recall selected data pages from the at least one low performance data storage element onto the at least one high performance data storage element. The controller also uses the meta data page to migrate selected data pages from the at least one high performance data storage element onto the at least one low performance data storage element.
In an alternative embodiment, the at least one data storage element includes a plurality of data storage elements of varying performance. The controller uses the meta data page to selectively store the data pages onto the at least one data storage element.
Further, in accordance with the above objects and other objects, the present invention provides a method of operating the intelligent data storage manager.
The above objects and other objects, features, and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the present invention when taken in connection with the accompanying drawings.